Septic rules and requirements in Snohomish County, Washington

Who issues septic permits in Snohomish County?

Snohomish County Health Department, Environmental Health Division, at 3020 Rucker Avenue, Suite 104, Everett, WA 98201, 425-339-5250. It is part of county government. The state writes the rules it applies.

The county's Health Department reviews septic designs and issues permits for homes and small businesses. The state handles larger systems on its own.

Snohomish County Health Department — Septic Permitting · checked 2026-09-23

What does a septic permit cost in Snohomish County?

$1,130 for a septic system permit, on the county's own schedule.

Applies to a new gravity or pump system.

The county charges more for a system the state health department must approve. It charges by connection for a community system. A new system also pays a permit fee before building starts. A change or a repair has no separate permit fee. The county's Board of Health sets these amounts. The state code sets none.

Snohomish County Board of Health Code § 1.40.090, On-Site Sewage Dispersal Systems · checked 2026-09-23

How long does approval take in Snohomish County?

5 weeks.

Applies to a new septic system application.

The county does not offer an expedited review. It updates this turnaround time as its workload changes.

Snohomish County Health Department — Septic Application Turnaround Times · checked 2026-09-23

Is the soil in Snohomish County suitable for a septic system?

USDA rates most of the county Very limited for septic absorption fields — 98.6% of the rated acres. A rating describes the ground, not a parcel. The county's site evaluation decides each lot.

• Very limited — 542,337 acres — 98.6% of 550,154 rated acres.
• Somewhat limited — 7,817 acres — 1.4% of 550,154 rated acres.
• Not rated — 54,329 acres, excluded from the denominator — mostly urban land and water.

USDA NRCS Soil Data Access (SSURGO) · checked 2026-09-16

Does Snohomish County inspect a septic system when a house is sold?

Before a sale, the seller must get a report of property transfer from the Health Department. A recent check of the system backs that report.

The county reviews the seller's inspection report first. It can ask for repairs before it issues the report. It also checks that a record drawing is on file. State law asks only for a check at the sale. That state rule starts later.

Snohomish County Board of Health Code, Ordinance No. BOH26-02, Chapter 5.60 · checked 2026-09-23

What Snohomish County sets itself

The state writes the code. Snohomish County adds the rules below. They are what makes this page differ from the Washington requirements.

• $1,130

  Applies to a new gravity or pump system.

  The county charges more for a system the state health department must approve. It charges by connection for a community system. A new system also pays a permit fee before building starts. A change or a repair has no separate permit fee. The county's Board of Health sets these amounts. The state code sets none.

  Snohomish County Board of Health Code § 1.40.090, On-Site Sewage Dispersal Systems · checked 2026-09-23

• Before a sale, the seller must get a report of property transfer from the Health Department. A recent check of the system backs that report.

  Applies to a sale of a home with a septic system, starting November 1, 2026.

  The county reviews the seller's inspection report first. It can ask for repairs before it issues the report. It also checks that a record drawing is on file. State law asks only for a check at the sale. That state rule starts later.

  Snohomish County Board of Health Code, Ordinance No. BOH26-02, Chapter 5.60 · checked 2026-09-23

• For a single home, the county sets a minimum number of soil log test holes. It requires at least three in the disposal area and two in the reserve area. Each hole must sit at least 50 feet from the next.

  Applies to a single home's septic system.

  The state rule asks only for enough soil logs, decided case by case. The county sets its own minimum count and spacing.

  Snohomish County Board of Health Code § 5.11.020, Site Identification and Preparation · checked 2026-09-23

• Snohomish County requires an installer or a pumper to pass a written exam. Each must score at least 70 percent. Then each passes a field test or an oral review. A monitoring expert needs two years of related work. Each expert also earns 10 hours of training a year. Every certificate expires each December 31 and must be renewed each year.

  The state tells every local health office to set up this approval process. It does not set an exam score, a work history length, or a renewal date. Snohomish County sets all three in its own code.

  Snohomish County Board of Health Code § 5.55.060, OSS Contractor Certification · checked 2026-09-23

Sources

Each figure above has a government source and a checked-on date. USDA's Soil Data Access service supplies the soil records. A script writes them, and nobody types them.

1. Snohomish County Health Department — Septic Permitting · checked 2026-09-23
2. Snohomish County Health Department — Septic · checked 2026-09-23
3. Snohomish County Board of Health Code § 5.11.020, Site Identification and Preparation · checked 2026-09-23
4. Snohomish County Board of Health Code § 5.55.060, OSS Contractor Certification · checked 2026-09-23
5. Snohomish County Board of Health Code § 1.40.090, On-Site Sewage Dispersal Systems · checked 2026-09-23
6. Snohomish County Health Department — Septic Application Turnaround Times · checked 2026-09-23
7. Snohomish County Health Department — Septic Permit Steps · checked 2026-09-23
8. Snohomish County Health Department — As-Built Records · checked 2026-09-23
9. Snohomish County Board of Health Code, Ordinance No. BOH26-02, Chapter 5.60 · checked 2026-09-23
10. Washington Administrative Code § 246-272A-0232 · checked 2026-09-23
11. Washington Administrative Code § 246-272A-0210 · checked 2026-09-23
12. USDA NRCS Soil Data Access (SSURGO) · checked 2026-09-16

Related pages

• Septic rules in Snohomish County
• Septic permits and fees in Snohomish County, Washington
• Soil and perc tests in Snohomish County, Washington
• Home-sale septic inspections in Snohomish County, Washington
• Septic rules and requirements in Washington